/**
 * @file
 * Ethernet Interface Skeleton
 *
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

/*
 * This file is a skeleton for developing Ethernet network interface
 * drivers for lwIP. Add code to the low_level functions and do a
 * search-and-replace for the word "ethernetif" to replace it with
 * something that better describes your network interface.
 */

#include "lwip/opt.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/pbuf.h"
#include "lwip/sys.h"
#include <lwip/stats.h>
#include <lwip/snmp.h>
#include "netif/etharp.h"
#include "netif/ppp_oe.h"
#include "err.h"
#include "ethernetif.h"

#include "main.h"
#include "stm32_eth.h"
#include <string.h>

/* TCP and ARP timeouts */
volatile int tcp_end_time, arp_end_time;

/* Define those to better describe your network interface. */
#define IFNAME0 's'
#define IFNAME1 't'

#define  ETH_DMARxDesc_FrameLengthShift           16
//#define  ETH_ERROR              ((u32)0)
//#define  ETH_SUCCESS            ((u32)1)

/**
 * Helper struct to hold private data used to operate your ethernet interface.
 * Keeping the ethernet address of the MAC in this struct is not necessary
 * as it is already kept in the struct netif.
 * But this is only an example, anyway...
 */
struct ethernetif
{
    struct eth_addr *ethaddr;
    /* Add whatever per-interface state that is needed here. */
    int unused;
};

/* Forward declarations. */
err_t  ethernetif_input(struct netif *netif);

#define ETH_RXBUFNB        4
#define ETH_TXBUFNB        8		//by xuwei 2->8

uint8_t MACaddr[6];
ETH_DMADESCTypeDef  DMARxDscrTab[ETH_RXBUFNB], DMATxDscrTab[ETH_TXBUFNB];/* Ethernet Rx & Tx DMA Descriptors */
uint8_t Rx_Buff[ETH_RXBUFNB][ETH_MAX_PACKET_SIZE], Tx_Buff[ETH_TXBUFNB][ETH_MAX_PACKET_SIZE];/* Ethernet buffers */

ETH_DMADESCTypeDef  *DMATxDesc = DMATxDscrTab;
extern ETH_DMADESCTypeDef  *DMATxDescToSet;
extern ETH_DMADESCTypeDef  *DMARxDescToGet;

typedef struct
{
    u32 length;
    u32 buffer;
    ETH_DMADESCTypeDef *descriptor;
} FrameTypeDef;

FrameTypeDef ETH_RxPkt_ChainMode(void);
u32 ETH_GetCurrentTxBuffer(void);
u32 ETH_TxPkt_ChainMode(u16 FrameLength);


/**
 * Setting the MAC address.
 *
 * @param netif the already initialized lwip network interface structure
 *        for this ethernetif
 */
void Set_MAC_Address(uint8_t *macadd)
{
    MACaddr[0] = macadd[0];
    MACaddr[1] = macadd[1];
    MACaddr[2] = macadd[2];
    MACaddr[3] = macadd[3];
    MACaddr[4] = macadd[4];
    MACaddr[5] = macadd[5];
    ETH_MACAddressConfig(ETH_MAC_Address0, macadd);
}


/**
 * In this function, the hardware should be initialized.
 * Called from ethernetif_init().
 *
 * @param netif the already initialized lwip network interface structure
 *        for this ethernetif
 */
static void
low_level_init(struct netif *netif)
{
    /* set MAC hardware address length */
    netif->hwaddr_len = ETHARP_HWADDR_LEN;
    /* set MAC hardware address */
    netif->hwaddr[0] =  MACaddr[0];
    netif->hwaddr[1] =  MACaddr[1];
    netif->hwaddr[2] =  MACaddr[2];
    netif->hwaddr[3] =  MACaddr[3];
    netif->hwaddr[4] =  MACaddr[4];
    netif->hwaddr[5] =  MACaddr[5];
    /* maximum transfer unit */
    netif->mtu = 1500;
    /* device capabilities */
    /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
    netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
    /* Initialize Tx Descriptors list: Chain Mode */
    ETH_DMATxDescChainInit(DMATxDscrTab, &Tx_Buff[0][0], ETH_TXBUFNB);
    /* Initialize Rx Descriptors list: Chain Mode  */
    ETH_DMARxDescChainInit(DMARxDscrTab, &Rx_Buff[0][0], ETH_RXBUFNB);
    /* Enable Ethernet Rx interrrupt */
    {
        int i;

        for(i = 0; i < ETH_RXBUFNB; i++)
        {
            ETH_DMARxDescReceiveITConfig(&DMARxDscrTab[i], ENABLE);
        }
    }
#ifdef CHECKSUM_BY_HARDWARE
    /* Enable the checksum insertion for the Tx frames */
    {
        int i;

        for(i = 0; i < ETH_TXBUFNB; i++)
        {
            ETH_DMATxDescChecksumInsertionConfig(&DMATxDscrTab[i], ETH_DMATxDesc_ChecksumTCPUDPICMPFull);
        }
    }
#endif
    /* Enable MAC and DMA transmission and reception */
    ETH_Start();
}

/**
 * This function should do the actual transmission of the packet. The packet is
 * contained in the pbuf that is passed to the function. This pbuf
 * might be chained.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
 * @return ERR_OK if the packet could be sent
 *         an err_t value if the packet couldn't be sent
 *
 * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
 *       strange results. You might consider waiting for space in the DMA queue
 *       to become availale since the stack doesn't retry to send a packet
 *       dropped because of memory failure (except for the TCP timers).
 */

static err_t
low_level_output(struct netif *netif, struct pbuf *p)
{
    struct pbuf *q;
    int l = 0;
    u8 *buffer = (u8 *)ETH_GetCurrentTxBuffer();

    for(q = p; q != NULL; q = q->next)
    {
        memcpy((u8_t *)&buffer[l], q->payload, q->len);
        l = l + q->len;
    }

    ETH_TxPkt_ChainMode(l);
    return ERR_OK;
}

/**
 * Should allocate a pbuf and transfer the bytes of the incoming
 * packet from the interface into the pbuf.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return a pbuf filled with the received packet (including MAC header)
 *         NULL on memory error
 */
static struct pbuf *
low_level_input(struct netif *netif)
{
    struct pbuf *p, *q;
    u16_t len;
    int l = 0;
    FrameTypeDef frame;
    u8 *buffer;

    p = NULL;
    frame = ETH_RxPkt_ChainMode();
    /* Obtain the size of the packet and put it into the "len"
       variable. */
    len = frame.length;

    buffer = (u8 *)frame.buffer;

    /* We allocate a pbuf chain of pbufs from the pool. */
    p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);

    if(p != NULL)
    {
        for(q = p; q != NULL; q = q->next)
        {
            memcpy((u8_t *)q->payload, (u8_t *)&buffer[l], q->len);
            l = l + q->len;
        }
    }


    /* Set Own bit of the Rx descriptor Status: gives the buffer back to ETHERNET DMA */
    frame.descriptor->Status = ETH_DMARxDesc_OWN;

    /* When Rx Buffer unavailable flag is set: clear it and resume reception */
    if((ETH->DMASR &ETH_DMASR_RBUS) != (u32)RESET)
    {
        /* Clear RBUS ETHERNET DMA flag */
        ETH->DMASR = ETH_DMASR_RBUS;
        /* Resume DMA reception */
        ETH->DMARPDR = 0;
    }


    return p;
}

/**
 * This function should be called when a packet is ready to be read
 * from the interface. It uses the function low_level_input() that
 * should handle the actual reception of bytes from the network
 * interface. Then the type of the received packet is determined and
 * the appropriate input function is called.
 *
 * @param netif the lwip network interface structure for this ethernetif
 */
err_t
ethernetif_input(struct netif *netif)
{
    err_t err;
    struct pbuf *p;
    /* move received packet into a new pbuf */
    p = low_level_input(netif);

    /* no packet could be read, silently ignore this */
    if(p == NULL)
    {
        return ERR_MEM;
    }

    err = netif->input(p, netif);

    if(err != ERR_OK)
    {
        LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
        pbuf_free(p);
        p = NULL;
    }

    return err;
}

/**
 * Should be called at the beginning of the program to set up the
 * network interface. It calls the function low_level_init() to do the
 * actual setup of the hardware.
 *
 * This function should be passed as a parameter to netif_add().
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return ERR_OK if the loopif is initialized
 *         ERR_MEM if private data couldn't be allocated
 *         any other err_t on error
 */
err_t
ethernetif_init(struct netif *netif)
{
    struct ethernetif *ethernetif;
    LWIP_ASSERT("netif != NULL", (netif != NULL));
    ethernetif = mem_malloc(sizeof(struct ethernetif));

    if(ethernetif == NULL)
    {
        LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n"));
        return ERR_MEM;
    }

#if LWIP_NETIF_HOSTNAME
    /* Initialize interface hostname */
    netif->hostname = "lwip";
#endif /* LWIP_NETIF_HOSTNAME */
    /*
     * Initialize the snmp variables and counters inside the struct netif.
     * The last argument should be replaced with your link speed, in units
     * of bits per second.
     */
    NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, 100000000);
    netif->state = ethernetif;
    netif->name[0] = IFNAME0;
    netif->name[1] = IFNAME1;
    /* We directly use etharp_output() here to save a function call.
     * You can instead declare your own function an call etharp_output()
     * from it if you have to do some checks before sending (e.g. if link
     * is available...) */
    netif->output = etharp_output;
    netif->linkoutput = low_level_output;
    ethernetif->ethaddr = (struct eth_addr *) & (netif->hwaddr[0]);
    /* initialize the hardware */
    low_level_init(netif);
    return ERR_OK;
}

/*******************************************************************************
* Function Name  : ETH_RxPkt_ChainMode
* Description    : Receives a packet.
* Input          : None
* Output         : None
* Return         : frame: farme size and location
*******************************************************************************/
FrameTypeDef ETH_RxPkt_ChainMode(void)
{
    u32 framelength = 0;
    FrameTypeDef frame = {0, 0};

    /* Check if the descriptor is owned by the ETHERNET DMA (when set) or CPU (when reset) */
    if((DMARxDescToGet->Status & ETH_DMARxDesc_OWN) != (u32)RESET)
    {
        frame.length = ETH_ERROR;

        if((ETH->DMASR & ETH_DMASR_RBUS) != (u32)RESET)
        {
            /* Clear RBUS ETHERNET DMA flag */
            ETH->DMASR = ETH_DMASR_RBUS;
            /* Resume DMA reception */
            ETH->DMARPDR = 0;
        }

        /* Return error: OWN bit set */
        return frame;
    }

    if(((DMARxDescToGet->Status & ETH_DMARxDesc_ES) == (u32)RESET) &&
            ((DMARxDescToGet->Status & ETH_DMARxDesc_LS) != (u32)RESET) &&
            ((DMARxDescToGet->Status & ETH_DMARxDesc_FS) != (u32)RESET))
    {
        /* Get the Frame Length of the received packet: substruct 4 bytes of the CRC */
        framelength = ((DMARxDescToGet->Status & ETH_DMARxDesc_FL) >> ETH_DMARxDesc_FrameLengthShift) - 4;
        /* Get the addrees of the actual buffer */
        frame.buffer = DMARxDescToGet->Buffer1Addr;
    }
    else
    {
        /* Return ERROR */
        framelength = ETH_ERROR;
    }

    frame.length = framelength;
    frame.descriptor = DMARxDescToGet;
    /* Update the ETHERNET DMA global Rx descriptor with next Rx decriptor */
    /* Chained Mode */
    /* Selects the next DMA Rx descriptor list for next buffer to read */
    DMARxDescToGet = (ETH_DMADESCTypeDef *)(DMARxDescToGet->Buffer2NextDescAddr);
    /* Return Frame */
    return (frame);
}

/*******************************************************************************
* Function Name  : ETH_TxPkt_ChainMode
* Description    : Transmits a packet, from application buffer, pointed by ppkt.
* Input          : - FrameLength: Tx Packet size.
* Output         : None
* Return         : ETH_ERROR: in case of Tx desc owned by DMA
*                  ETH_SUCCESS: for correct transmission
*******************************************************************************/
u32 ETH_TxPkt_ChainMode(u16 FrameLength)
{
    /* Check if the descriptor is owned by the ETHERNET DMA (when set) or CPU (when reset) */
    if((DMATxDescToSet->Status & ETH_DMATxDesc_OWN) != (u32)RESET)
    {
        /* Return ERROR: OWN bit set */
        return ETH_ERROR;
    }

    /* Setting the Frame Length: bits[12:0] */
    DMATxDescToSet->ControlBufferSize = (FrameLength & ETH_DMATxDesc_TBS1);
    /* Setting the last segment and first segment bits (in this case a frame is transmitted in one descriptor) */
    DMATxDescToSet->Status |= ETH_DMATxDesc_LS | ETH_DMATxDesc_FS;
    /* Set Own bit of the Tx descriptor Status: gives the buffer back to ETHERNET DMA */
    DMATxDescToSet->Status |= ETH_DMATxDesc_OWN;

    /* When Tx Buffer unavailable flag is set: clear it and resume transmission */
    if((ETH->DMASR & ETH_DMASR_TBUS) != (u32)RESET)
    {
        /* Clear TBUS ETHERNET DMA flag */
        ETH->DMASR = ETH_DMASR_TBUS;
        /* Resume DMA transmission*/
        ETH->DMATPDR = 0;
    }

    /* Update the ETHERNET DMA global Tx descriptor with next Tx decriptor */
    /* Chained Mode */
    /* Selects the next DMA Tx descriptor list for next buffer to send */
    DMATxDescToSet = (ETH_DMADESCTypeDef *)(DMATxDescToSet->Buffer2NextDescAddr);
    /* Return SUCCESS */
    return ETH_SUCCESS;
}


/*******************************************************************************
* Function Name  : ETH_GetCurrentTxBuffer
* Description    : Return the address of the buffer pointed by the current descritor.
* Input          : None
* Output         : None
* Return         : Buffer address
*******************************************************************************/
u32 ETH_GetCurrentTxBuffer(void)
{
    /* Return Buffer address */
    return (DMATxDescToSet->Buffer1Addr);
}
